Acetyl chloride → Diphenylmethyl 7-(2-thienylacetamido)-3-(1-acetoxyethyl)-3-cephem-4-carboxylate

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Reaction Steps

Similarly, polar isomer B of diphenylmethyl 7-(2-thienylacetamido)-3-(1-acetoxyethyl)-3-cephem-4-carboxylate 1-oxide (69 mg) is reduced with stannous chloride dihydrate (66 mg) and acetyl chloride (0.28 ml) in N,N-dimethylformamide (2.1 ml) for 15 minutes to give stereoisomer B of diphenylmethyl 7-(2-thienylacetamido)-3-(1-acetoxyethyl)-3-cephem-4-carboxylate (71 mg). m.p. 72°-80° C. Yield: 83.4%. IR: νmaxCHCl 3 3396, 1787, 1731, 1687, 1508 cm-1. NMR: δCDCl 3 1.27d(6.5Hz) 3H, 1.88s3H, 3.40br-s2H, 3.83s2H, 4.95d(5Hz)1H, 5.72q(9;5Hz) 1H, 6.11q(6.5Hz)1H, 6.48d(9Hz)1H, 6.9-7.5m14H.

Provenance & Evidence